@article{MZ_1989__201_4_174035,
     author = {Yunmei Chen},
     title = {The {Weak} {Solutions} to the {Evolution} {Problems} of {Harmonic} {Maps.}},
     journal = {Mathematische Zeitschrift},
     pages = {69--74},
     publisher = {mathdoc},
     volume = {201},
     number = {4},
     year = {1989},
     zbl = {0685.58015},
     url = {http://geodesic.mathdoc.fr/item/MZ_1989__201_4_174035/}
}